The invention relates to a hot air generator.
A hot air generator generally appears as an elongated body longitudinally crossed by a conduit in which flows gas to be inflamed. The body is extended by a generally hollow burner portion into which opens the conduit. The burner portion is provided at its free end with gas combustion means capable of setting fire to the gas. Such a burner is for example described in document EP 1 795 803.
More generally, it may be used for heating thermosetting, thermoformable, heat-shrinkable materials, materials which are caused to adhere by heat and the like.
For example, such a hot generator is advantageously used for laying or making asphalt.
It may also be used in the construction field by roofers for covering roofs with thermosetting impervious material, which is generally found in the form of wound strips.
The generator may further be used in the field of logistics and transportation for shrinking plastic films surrounding pallets of goods.
The generator may also be used for heating premises.
Although the generator described in document EP 1 795 803 is satisfactorily efficient, changes in the legislation relating to the use of such hand generators recommend the use of hot air generators with no apparent flame.
A solution in order to comply with the new legislation is to project compressed air to be heated towards the flame when the latter is generated inside a hot air generator so that it cannot emerge, in order to transfer calories to the compressed air which flows out of the generator in a hot condition. Thus, the material to be heated is not in contact with the flame but with hot air.
This solution has the drawback of generating a high cost of use for a large consumption of compressed air.
Another drawback lies in safety because gas may be transported into the burner even if there is no longer any compressed air therein.